Abstract

Rice noodles are a widely consumed food in Asia, including in Thailand. Nevertheless, this popular food is high in carbohydrates, but low in dietary fiber. Pomelo by-products (PBP) are a highly insoluble dietary fiber (IDF) source that has been investigated for fiber-fortified rice noodles with health benefits. This study was conducted to prove theeffects of IDF in PBP at different levels (10 and 12.5%) of the rice flour and different particle size distributions (180 and 150 mm) on themoisture content, water activity, cooking weight, cooking loss, textural and sensory evaluation.The addition of IDF-PBP to rice noodles was found to have significant (p<0.05) effects on the colors of a*, b*, while cooking weights wasincreased in all samples. Cooking loss and tensile strength also decreased as compared to the control. Themoisture content and water activity of rice noodles were between 8.66-9.14% and 0.32-0.36, respectively.When considering the addition of IDF-PBP at 10 and 12.5%, the findings revealed that the sample was not significantly different (p>0.05) in the cooking weight. However, when the particle size was reduced, the cooking weightincreased. Cooking lossdecreased when IDF-PBP was increased, and the particle size was reduced. The texture of the particle size distribution was 180 and 150 mm at levels 10% in tensile strength and showed no  significant difference (p>0.05) as comparedto the control rice noodles.Rice noodles with 10% IDF-PBP particle size distribution 150 mm showed the highest overall acceptability in sensory evaluation. The results revealed that adding IDF-PBP to rice noodles increased the total dietary fiber content at 9.44% and the insoluble dietary fiber content at 8.71% as compared to the control rice noodles. Based on the results, the addition of IDF-PBP to rice noodles can lead consumers to conclude that the product is healthy.